The Betrayed Beast (MHA x Black Clover x Demon Slayer)

Chapter 1: A Violent Assault

After a huge fight against the Elves and to a Devil, Asta can be seen sleeping in his room in the Black Bulls base. While sleeping, his demon suddenly awakened from his thoughts and detected something violent and disturbing aura from somewhere

"This aura... It can't be. What does this demon up to and why I can sense a huge demonic aura around the Clover Kingdom?" The demon of Asta asked from his own world in Asta's body. One girl from above the Clover Kingdom can be seen floating in the sky and sees everyone fixing their houses, buildings that were destroyed by the battle of the Magic Knights against the elves.

"Oh? So you're telling me that around this kingdom, there is this demon who can defeat the Dark Triad? Well, if you say so, I'll be making something special to eliminate the one who was possessed by this demon then." The girl named Vanica said.

"I have a great idea! How about... we are going to use the Magic Knights of this kingdom and let these people kill this boy?" The demon known to be Megicula said on Vanica's mind.

"In what way?" Vanica asked while putting her finger in her chin.

"THIS!!" Megicula exclaimed as black aura can be seen formed from Vanica's hand and fired a huge black aura in the sky, dark enough to cover the bright sun of the day.

"Wh-What's this black mist?!" Fuegoleon asked while commanding some Magic Knights to remove some rubble from the destroyed building.

"What is this?" Nozel asked from his home where some of his servants can be seen fixing their broken homes.

"This aura... Marx, can you tell me what's this magic?" Julius asked.

"Sorry but... I can't tell you the answer, Julius sama." Marx replied.

"What do you mean?" Julius asked.

"Cigam Sthgink fo eht revolc modgnik, llik dna etanimile eht kcalB slluB cigam thgink atsA sa eh sah a eguh niotcennoc htiw su snomed fo eht edapS modgniK ohw lliw noos ekat revo dna yorysed eht revolc modgnik! Fi uoy tnaw ot eb deraps morf ruo niosavni, llik mih dna gnirb sih daeh ot su!" Vanica voiced by Megicula announced in its demonic language to the whole Clover Kingdom and now fires a huge amount of rays towards the Magic Knights of the Clover Kingdoms and to all the captains it. Everyone's eyes are now pure red and have a devilish face among them as Megicula manipulates their minds and gave them an objective that would make them grow angry and berserk.

"We have one mission to do, KILL ASTA and Save the Clover Kingdom!" All of the Magic Knights and Captains from the whole Clover Kingdome yelled at Vanica from the sky.

"Well then. What are you doing? Find him and kill him! Happy killing!" Vanica exclaimed with excitement.

"Raaaah!!" Marx roared as he used his magic to break through the window and now all of the Magic Knights are now directed to the Black Bulls base where Asta is located. Julius can be seen down on the ground and is a bit terrified about what he just saw.

"Wh-What's going on? Marx, what are you doing?" Julius asked. In the Black Bulls base, Asta can be seen snoring in his sleep after a tiring battle with the elves and to a devil. His demon can be seen waking him up from his sleep as he is about to warn him about the aura he felt.

"Boy! Hey! Stop sleeping, something's bad is gonna happen to you!" The demon of Asta yelled but Asta still didn't care and continued to sleep. A huge bang from his door can be heard as Magna and Luck now charged at the sleeping Asta with their fiery red eyes.

"Die, you traitor!" Magna yelled.

"Such a worthy one to kill!" Luck added.

"Asta!!!" The demon roared on Asta's thoughts as he has finally woke up and quickly sees his two comrades attacking him with murderous intent.